Wheel

Abstract

The wheel is all-metal, and is suitable for use on the moon. The wheel includes tread-plates mounted on leaf-springs, which deflect to permit suspension movement. The leaf-springs are flexible, light, and thin, yet are made strong enough to cope with heavy traction forces by the provision of hoop-cables, which link all the tread-plates together.

The invention claimed is: 
     
       1. Wheel, wherein:
 the wheel includes a rim, which is fast to a hub of the wheel, for rolling motion about a wheel axis; 
 the wheel includes many tread-plates; 
 the wheel includes resiliently flexible tread-springs; 
 proximal ends of the tread-springs are fast to the rim; 
 distal ends of the tread-springs are fast to the tread-plates, whereby the tread-plates and tread-springs form tread-units; 
 the tread-units are so configured that: 
 (a) the tread-plates are urged radially outwards, with respect to the axis of the wheel, by the resilience of the tread-springs; and 
 (b) the tread-plates can move, individually, radially inwards against the resilience of the tread-springs; 
 the tread-units are arranged in a hoop-set, or in hoop-sets; 
 in respect of the or each hoop-set of tread-plates: 
 (a) the hoop-set is so configured that each tread-plate of the hoop-set lies circumferentially between adjacent tread-plates of the hoop-set; 
 (b) the hoop-set includes a hoop-cable; 
 (c) each one of the tread-plates that make up the hoop-set is fast to the hoop-cable; 
 (d) the hoop-cable is of so dimensioned that, the wheel being unloaded and the tread-plates being urged radially outwards by the tread-springs, the hoop-cable is under hoop-tension; and 
 (e) the tread-plates are each fastened to the hoop-cable in such manner that, the wheel being unloaded, adjacent tread-plates can approach but cannot separate, circumferentially. 
 
     
     
       2. A wheel as claimed in  claim 1  wherein the wheel is metal. 
     
     
       3. A wheel as claimed in  claim 1  wherein the wheel is all metal. 
     
     
       4. A wheel as claimed in  claim 1 , wherein:
 the tread-plates are independent; 
 the resiliently flexible tread-springs are independent leaf springs; 
 distal ends of the tread-springs are fast to the tread-plates, whereby the tread-plates and tread-springs form independent tread-units; 
 the tread-springs are so configured that: 
 (a) the tread-plates are urged radially outwards, with respect to the axis of the wheel, by the resilience of the tread-springs; and 
 (b) the tread-plates can move, individually, radially inwards against the resilience of the tread-springs; 
 (c) the tread-units are restrained, individually, by respective tread springs against movement parallel to the wheel axis; 
 the hoop cable is inelastic and flexible. 
 
     
     
       5. A wheel as claimed in  claim 4  wherein the wheel is metal. 
     
     
       6. A wheel as claimed in  claim 4  wherein the wheel is all metal. 
     
     
       7. An all metal wheel as claimed in  claim 6 , wherein the tread units are held firmly, individually, by respective tread-springs in position axially relative to the wheel. 
     
     
       8. An all metal wheel as claimed in  claim 7 , wherein the wheel is so structured that, when the wheel is in an operational loaded condition, and the wheel is rolling over the ground:
 the tread-plate of a bottom one of the tread-units makes direct touching contact with the ground; 
 the tread-spring of the bottom tread-unit deflects radially inwards relative to the axis of the wheel; 
 in the other tread-units that are clear of the ground, the tread-springs urge the tread-plates radially outwards, against the tension of the hoop cable. 
 
     
     
       9. An all metal wheel as claimed in  claim 8 , wherein:
 each tread-unit comprises one tread-plate and just one tread-spring that is fast to the rim and to the tread-plate; and 
 the wheel includes left and right hoop-sets of tread-units, having respective hoop-cables. 
 
     
     
       10. An all metal wheel as claimed in  claim 9 , wherein:
 in the tread-units of the left hoop-set: 
 (a) the left tread-plates lie to the left of the rim; 
 (b) the proximal ends of the left tread-springs are fast to the right side of the rim; 
 (c) the left tread-springs extend over the rim, and their distal ends are fast to the left tread-plates; 
 in the tread-units of the right hoop-set: 
 (a) the right tread-plates lie to the right of the rim; 
 (b) the proximal ends of the right tread-springs are fast to the right side of the rim; 
 (c) the right tread-springs extend over the rim, and their distal ends are fast to the right tread-plates. 
 
     
     
       11. An all metal wheel as claimed in  claim 8 , wherein:
 the wheel includes just one hoop-set of tread-units; 
 each tread-unit comprises left and right tread-springs and just one tread-plate; 
 the left and right tread-springs are fast to the rim and to the tread-plate; 
 left and right hoop-cables are fast to left and right ends of the tread-plates. 
 
     
     
       12. An all metal wheel as claimed in  claim 11 , wherein:
 the tread-plates span across the width of the wheel, over the rim; 
 the proximal ends of the left tread-springs are fast to the left side of the rim; 
 the distal ends of the left tread-springs are fast to the left end of the tread-plate; 
 the proximal ends of the right tread-springs are fast to the right side of the rim; 
 the distal ends of the right tread-springs are fast to the right end of the tread-plate. 
 
     
     
       13. An all metal wheel as claimed in  claim 8 , wherein:
 the wheel includes rim-brackets, which are fast to the rim; 
 each rim-bracket is formed with a rim-bracket surface, to which the proximal ends of the tread-springs are fast. 
 
     
     
       14. An all metal wheel as claimed in  claim 8 , wherein, in respect of each tread-unit, the or each tread-spring is a leaf-spring, being of sheet metal. 
     
     
       15. An all metal wheel as claimed in  claim 14 , wherein the wheel is so configured that:
 the thickness-dimension of the leaf-spring lies predominantly radially with respect to the wheel; 
 the width-dimension of the leaf-spring lies in a plane that is predominantly tangential with respect to the wheel; and 
 the length-dimension lies predominantly parallel to the wheel-axis of the wheel. 
 
     
     
       16. An all metal wheel as claimed in  claim 14 , wherein:
 the leaf-spring has a flex-length comprising the length of that portion of the tread-spring that, in operation, is capable of undergoing resilient deflection; and 
 the flex-length is half of the overall width of the wheel, or more. 
 
     
     
       17. An all metal wheel as claimed in  claim 16 , wherein, at every point on the flex-length of the leaf-spring, a tangent to the leaf-spring at that point lies at an angle that is within thirty degrees of being parallel to the wheel-axis of the wheel. 
     
     
       18. An all metal wheel as claimed in  claim 16 , wherein:
 each point on the flex-length of each leaf-spring has a tread-spring radius, being a radial line joining the wheel-axis to that point of the tread-spring; 
 the tread-unit is so mounted with respect to the rim that the plane of the sheet metal of the tread-spring at the point lies within thirty degrees of being perpendicular to the tread-spring radius at the point. 
 
     
     
       19. An all metal wheel as claimed in  claim 14 , wherein:
 a wheel-radius of a point in the wheel is a line that is perpendicular to the wheel-axis, and extends from the wheel-axis to the point; 
 the wheel-radius of the proximal end of the leaf-spring is shorter than the wheel-radius of the distal end. 
 
     
     
       20. An all metal wheel as claimed in  claim 8 , wherein the hoop-cables are of such hoop-length that the actually-enabled-deflection of the tread-spring is between thirty percent and seventy percent of the overall deflection-capability of the tread-spring. 
     
     
       21. An all metal wheel as claimed in  claim 8 , wherein:
 in respect of each tread-unit the or each tread-plate has no physical attachment to the rim except through the respective tread-springs; and 
 the hoop-cables have no direct physical connection to the rim. 
 
     
     
       22. An all metal wheel as claimed in  claim 8 , wherein the rim is part of a unitary integrated hub-spokes-rim component of the wheel. 
     
     
       23. An all metal wheel as claimed in  claim 8 , wherein all components of the wheel are of metal and
 the tread-plates are of titanium; 
 the tread-springs are of spring-steel.